After last week's shocking loss to the Cyclones, No. 12 Oklahoma (4-1) is under enormous pressure to win out just to have a shot at reaching the College Football Playoff. Texas (3-2), meanwhile, is undefeated in Big 12 play entering Saturday's game at the Cotton Bowl in Dallas (ESPN and ESPN App, 3:30 p.m. ET).

"We've got to quit worrying about the expectations of the outside world and all that and just go do the absolute best that we can," Riley said.

Editor's Picks

Will the balance of power shift in the Big Ten? Which Power 5 conference will have its heart broken? Are we headed to a rematch of epic proportions? Here are a dozen predictions for the second half of the season.

So yeah, the Big 12 might be on edge. For example, Texas has won six of the last nine meetings between these teams when the Longhorns are unranked and the Sooners are ranked. A Texas win on Saturday would knock OU out of the playoff race for good.

No. 6 TCU (5-0), the lone undefeated team in the Big 12, should be wary of its trip to Kansas State, especially after an emotional home win against West Virginia.

Not convinced?

Consider this history lesson, from ESPN's Stats & Information: This is the latest into a season in which we've had no matchups of AP-ranked teams since Week 12 of 2009, the weekend before Thanksgiving. That week, four ranked teams lost to unranked opponents, including two teams that were ranked in the top 15.

Who else is on upset watch in Week 7? The following games are listed in order of most likely to least likely to produce an upset:

play

0:47

Who will win the Red River Showdown?

Both Lincoln Riley and Tom Herman will make their first appearance as head coaches in one of college football's most storied rivalries. Will Oklahoma bounce back from a stunning loss last week? Or will Texas deal OU a crushing blow to its playoff hopes?

This is a critical game in the ACC's Coastal Division race. The Georgia Tech Yellow Jackets could be 4-0 and ranked if they had converted a two-point conversion against Tennessee in their opener. Undefeated Miami earned an important win over rival Florida State in Tallahassee last week, but the Hurricanes are hurting. Receiver Ahmmon Richards could be out with an aggravated hamstring injury, starting right guard Navaughn Donaldson is questionable (ankle), and top running back Mark Walton is out for the season after injuring his ankle against the Seminoles.

Georgia Tech has won three straight since losing to the Vols, a game that Tech coach Paul Johnson said his team "kind of gift-wrapped and gave away." Still, he's not quite sure what to make of the Yellow Jackets, calling his team "a little bit of an enigma." Georgia Tech would become an interesting proposition with a victory over the Hurricanes. The Yellow Jackets have the most difficult remaining schedule in FBS, according to ESPN's Football Power Index, with games against No. 2 Clemson, No. 15 Virginia Tech and No. 4 Georgia still to play.

If Oklahoma loses, it's done as far as the CFP goes. The Sooners are already on the outside looking in, but this would be the final dagger in their playoff hopes, and it's only the midpoint of the season. Oklahoma's loss last week was damaging for the Big 12 as a whole, as the league's chances to produce a champion with one or fewer losses fell from 67 to 32 percent, according to FPI.

FPI says: With a win, Oklahoma's chances of winning the Big 12 will rise from 43 percent to 48 percent, but with a loss, those chances will fall to about 23 percent.

One of the secrets to the Horned Frogs' success is that they are converting 58.3 percent of their third-down opportunities, the highest rate in FBS. However, K-State's Bill Snyder is a Hall of Fame coach with a team that doesn't typically beat itself. The Wildcats enter the game ranked 11th nationally in turnover margin (plus-six).

"It doesn't matter if you're 0-5 or 5-0, they're hard to handle," said TCU coach Gary Patterson, "so we've got to get ready to play." These teams have split their last 10 meetings, but K-State hasn't defeated a top-10 team at home since 2006.

"Nobody blinked," coach Ed Orgeron said. "I think the staff came together more last week than any week. The team came together. The leadership evolved. Through adversity, we became stronger. We felt that going into the game. Our guys say, 'We are not getting on this plane unless we win the game.' That was new."

We'll see whether that carries over to LSU's visit from Auburn, which has not won in Baton Rouge since 1999. Auburn is off to a hot start in SEC play, outscoring opponents 144-47 in three league wins, and quarterback Jarrett Stidham has thrown five touchdown passes and no interceptions in that span, posting a Total QBR of 96.5.

This is the first of three straight road games for Auburn, and to be taken seriously as a challenger to Alabama in the SEC West, Auburn can't lose to a beleaguered LSU team, no matter how inspired.

FPI says: Auburn is favored to win each of its next three road games by at least 70 percent.

Don't look ahead, USC. The Trojans travel to Notre Dame on Oct. 21, but it won't mean much for their CFP hopes if they head into that game with two losses. USC has no margin for error after losing to Washington State, but the Trojans have an 84 percent chance to win the Pac-12 South, and a win over the Utes would set them on track for that. USC's problem is that quarterback Sam Darnold has already thrown nine interceptions and the Trojans have 13 total turnovers. That could be problematic against the Utes and the Fighting Irish, who have each forced 14 turnovers, tied for fourth-most in FBS.

Utah has won two of the past three meetings between these teams. Last year, Utah handed USC its third loss of the season with a thrilling come-from-behind win. The Trojans squandered a 27-17 fourth-quarter lead. They didn't lose again until Sept. 29 of this season against Wazzu.